Melissa A Liebert
Biographic Data
| ID | 3743215 |
|---|---|
| NAME | Melissa A Liebert |
| GIVEN NAMES | Melissa A |
| FAMILY NAME | Liebert |
| SIGNATURE | LIEBERT M A |
| AFFILIATIONS | Department of Anthropology Northern Arizona University Flagstaff Arizona USA |
| ORCID | 0000-0001-8013-6773 |
| VERIFIED | Yes |
| TOTAL WORKS | 31 |
| TOTAL CITATIONS | 98 |
| WORKS AS AUTHOR | 31 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 2011 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 5 |
Market Integration and Reproductive Transitions Among Indigenous Shuar and Neighboring Nonindigenous Ecuadorians in Amazonian Ecuador
OBJECTIVE: Global reproductive transitions are well documented, yet less is known about how neighboring populations with divergent histories and exposure to market integration (MI) experience them. This study examines how sociocultural and economic proxies of MI predict variation in reproductive outcomes among indigenous Shuar and nonindigenous Ecuadorian mestizos (Colonos) from Amazonian Ecuador, focusing on menarcheal age, age at first birth, p…
Navigating Practical, Political, and Ethical Challenges of Long‐Term Human Biology Field Research
Major advances in understanding human biology and health have been made possible by long‐term field research projects with Indigenous peoples, whose ecological settings and lifeways are distinct from majority populations in high‐income settings. Long‐term fieldwork is central to human biology, yet much about this research approach remains opaque. This paper considers a single long‐term study—the Shuar Health and Life History Project in Amazonian …
Impaired Intestinal Function Among Indigenous Shuar Children of Amazonian Ecuador
Intestinal function appears to be considerably impaired among school-age Shuar children living in a low-resource, rural setting. Children living in unsanitary, non-industrialized contexts may routinely experience intestinal permeability-related immune activation and malabsorption-related energy/nutrient loss. More research is needed to explore the breadth of global variation in children's intestinal function and to investigate its many evolutiona…
Oxidative Stress and Its Relationship With Market Integration and Pathogen Exposure Among Indigenous Shuar Children of Amazonian Ecuador
These findings suggest that MI, including its impact on pathogen exposure and physiology, is an important driver of global variation in childhood OS and related disparities in phenotype and health
Soil‐Transmitted Helminths and the Intricacies of Immunoregulation
OBJECTIVES: The old friends hypothesis (OFH) examines connections between the global increase in immunoregulatory diseases (e.g., allergy and autoimmunity) and reduced exposure to immune-priming symbionts like soil-transmitted helminths. Helminth species, however, vary in their effects on hosts and should be considered separately. We examined relationships between species-specific helminth infection and circulating biomarkers of adaptive immune a…
Somatic Symptoms Are Associated With Elevated Blood Pressure and Epstein–Barr Virus Antibodies Among Shuar of the Ecuadorian Amazon
INTRODUCTION: This study tests the hypothesis that self-reported somatic symptoms are associated with biomarkers of stress, including elevated blood pressure and suppressed immune function, among Shuar adults living in the Ecuadorian Amazon. METHODS: Research was conducted in three Shuar communities in the Upano Valley of the Ecuadorian Amazon and included the collection of biomarkers and a structured morbidity interview. Participants self-report…
Testosterone, 8‐Oxo‐2′‐Deoxyguanosine (8‐OHdG) and Cu/Zn Superoxide Dismutase (SOD) in Adult Shuar Males of Amazonian Ecuador
Objectives Reproductive effort incurs the cost of biological aging and morbidity by compromising somatic maintenance when key resources are limited. Oxidative stress is positively correlated with reproductive effort in adult human females and non‐human male animal models, but human males are understudied. We hypothesized that due to its anabolic and metabolic promotion of reproductive effort in human males, testosterone would be positively associ…
Circulating Epstein–Barr Virus Antibody Levels as a Biomarker of Socioecological Adversity in Amazonian Ecuador
OBJECTIVES: Circulating Epstein-Barr virus antibodies (EBV-Ab) are used as a biomarker of chronic stress in high-income settings, but their relevance in environments with a high burden of infectious disease, nutritional constraints, and limited resources is less clear. We investigated EBV-Ab as a biomarker of adversity in a setting where local ecology and economy may affect immune development differently than in wealthy countries. METHODS: We mea…
Salivary Testosterone, Age, and Adiposity Associations Among Shuar Males in Amazonian Ecuador Challenge Assumptions of “Normal” Testosterone Patterns
Objectives Adult male testosterone concentrations in high income countries often decrease with age and adiposity, a pattern typically viewed as “normal.” However, testosterone is expected to be adaptively regulated within the range of resource constrained, high pathogen, natural fertility conditions across which it evolved to function. We therefore examine associations among testosterone diurnal variation, age, and adiposity among Indigenous Shua…
Variation in diurnal cortisol patterns among the Indigenous Shuar of Amazonian Ecuador
This study expands the documented range of global variation in HPA axis activity and diurnal cortisol production and provides important insights into the plasticity of human stress physiology across diverse developmental and socioecological settings
Homeless Opioid Treatment Clients Transitioning to Dependent and Independent Housing
Purpose: Homeless opioid treatment clients who transition into housing generally demonstrate better outcomes, but housing environments vary widely and may not benefit racial/ethnic minority populations equally. We sought to identify how race/ethnicity moderates the association between positive opioid treatment response and moving into dependent or independent living environments. Methods: We used the Treatment Episode Dataset-Discharges (2018–201…
Low prevalence of anemia among Shuar communities of Amazonian Ecuador
OBJECTIVE: Anemia is an important global health challenge. We investigate anemia prevalence among Indigenous Shuar of Ecuador to expand our understanding of population-level variation, and to test hypotheses about how anemia variation is related to age, sex, and market integration. METHODS: Hemoglobin levels were measured in a total sample of 1650 Shuar participants (ages 6 months to 86 years) from 46 communities between 2008 and 2017 to compare …
Age‐related patterns of cytomegalovirus antibodies accompanying Epstein‐Barr virus co‐infection
OBJECTIVE: Cytomegalovirus (CMV) infection is associated with age-related chronic disease, and co-infection with Epstein-Barr virus (EBV) may compound disease risk. We aimed to assess the frequency of CMV infection and its relationship with age among EBV seropositive individuals in an Indigenous Amazonian population. METHODS: We report concentrations of CMV and EBV antibodies in dried blood spot samples collected from 157 EBV positive Shuar parti…
Biocultural Strategies for Measuring Psychosocial Stress Outcomes in Field-based Research
The goal of assessing psychosocial stress as a process and outcome in naturalistic (i.e., field) settings is applicable across the social, biological, and health sciences. Meaningful measurement of biology-in-context is, however, far from simple or straightforward. In this brief methods review, we introduce theoretical framings, methodological conventions, and ethical concerns around field-collection of markers of psychosocial stress that have em…
Disparities in bone density across contemporary Amazonian forager‐horticulturalists
OBJECTIVES: This study investigates bone density across the life course among Bolivian Tsimane and Ecuadorian Shuar of Amazonia. Both groups are rural, high-fertility forager-horticulturalists, with high lifetime physical activity levels. We test whether Tsimane and Shuar bone density patterns are different from each other, and if both groups are characterized by lower osteoporosis risk compared to U.S. references. METHODS: Anthropometric and cal…
Soil‐transmitted helminth infection and intestinal inflammation among the Shuar of Amazonian Ecuador
OBJECTIVES: Little research exists documenting levels of intestinal inflammation among indigenous populations where exposure to macroparasites, like soil-transmitted helminths (STHs), is common. Reduced STH exposure is hypothesized to contribute to increased prevalence of elevated intestinal inflammation in wealthy nations, likely due to coevolutionary histories between STHs and human immune systems that favored anti-inflammatory pathways. Here, …
Tradeoffs between immune function and childhood growth among Amazonian forager-horticulturalists
Significance The energetic impact of immune function on human growth remains unclear. Using data from Amazonian forager-horticulturalists, we show that diverse, low-level immune activity predicts reduced childhood growth over periods of competing energy use ranging from 1 wk to 20 mo. We also demonstrate that modest body fat stores (i.e., energy reserves) protect children from the particularly detrimental impact of acute inflammation on growth. T…
Food insecurity partially mediates associations between social disadvantage and body composition among older adults in india
OBJECTIVE: Our objective was to test whether food insecurity mediates cross-sectional associations between social disadvantage and body composition among older adults (aged 50+) in India (n = 6556). METHODS: Adjusting for key sociodemographic and dietary variables, we examined whether markers of social disadvantage (lower educational attainment, lower household wealth, belonging to a disadvantaged caste/tribe, and belonging to a minority religion…
Accelerometer‐measured physical activity among older adults in urban I ndia
OBJECTIVES: Accelerometry provides researchers with a powerful tool to measure physical activity in population-based studies, yet this technology has been underutilized in cross-cultural studies of older adults. The present study was conducted among older adults in an urban setting in India with the following three objectives: (1) to compare average activity levels obtained through different durations of monitoring (1, 3, and 7 days); (2) to docu…
Physical growth of the shuar
OBJECTIVES: Information concerning physical growth among small-scale populations remains limited, yet such data are critical to local health efforts and to foster basic understandings of human life history and variation in childhood development. Using a large dataset and robust modeling methods, this study aims to describe growth from birth to adulthood among the indigenous Shuar of Amazonian Ecuador. METHODS: Mixed-longitudinal measures of heigh…
Perceived Income Adequacy and Well-being Among Older Adults in Six Low- and Middle-Income Countries
As expected, income adequacy was correlated with SRH and QOL. However, the relationship between age and income adequacy varied cross-culturally, potentially due to differences in familial and governmental financial support
The application of knemometry to measure childhood short‐term growth among the indigenous Shuar of Ecuador
OBJECTIVES: Knemometry, the precise measurement of lower leg (LL) length, suggests that childhood short-term (e.g., weekly) growth is a dynamic, nonlinear process. However, owing to the large size and complexity of the traditional knemometer device, previous study of short-term growth among children has been restricted predominantly to clinical settings in industrialized Western nations. The aim of the present study is to address this limitation …
Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador
This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth and health among the Shuar and other indigenous Amazonian populations
The impact of multimorbidity on adult physical and mental health in low- and middle-income countries
BACKGROUND: Chronic diseases contribute a large share of disease burden in low- and middle-income countries (LMICs). Chronic diseases have a tendency to occur simultaneously and where there are two or more such conditions, this is termed as 'multimorbidity'. Multimorbidity is associated with adverse health outcomes, but limited research has been undertaken in LMICs. Therefore, this study examines the prevalence and correlates of multimorbidity as…
Determining osteoporosis risk in older C olono adults from rural A mazonian E cuador using calcaneal ultrasonometry
OBJECTIVE: Low bone density and osteoporosis prevalence, while well-documented in wealthy nations, are poorly studied in rural, non-clinical contexts in economically developing regions such as Latin America. This study contributes preliminary osteoporosis risk data for a rural Colono (mestizo) population from Amazonian Ecuador. METHODS: Anthropometrics were collected for 119 adult participants (74 females, 45 males [50-90 years old]). Heel bone d…
Implications of market integration for cardiovascular and metabolic health among an indigenous Amazonian Ecuadorian population
This study provides evidence that MI among Shuar is not a uniformly negative process but instead produces complex cardiovascular and metabolic health outcomes
Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador
This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth and health among the Shuar and other indigenous Amazonian populations
Disparities in bone density across contemporary Amazonian forager‐horticulturalists
OBJECTIVES: This study investigates bone density across the life course among Bolivian Tsimane and Ecuadorian Shuar of Amazonia. Both groups are rural, high-fertility forager-horticulturalists, with high lifetime physical activity levels. We test whether Tsimane and Shuar bone density patterns are different from each other, and if both groups are characterized by lower osteoporosis risk compared to U.S. references. METHODS: Anthropometric and cal…
Perceived Income Adequacy and Well-being Among Older Adults in Six Low- and Middle-Income Countries
As expected, income adequacy was correlated with SRH and QOL. However, the relationship between age and income adequacy varied cross-culturally, potentially due to differences in familial and governmental financial support
Soil‐transmitted helminth infection and intestinal inflammation among the Shuar of Amazonian Ecuador
OBJECTIVES: Little research exists documenting levels of intestinal inflammation among indigenous populations where exposure to macroparasites, like soil-transmitted helminths (STHs), is common. Reduced STH exposure is hypothesized to contribute to increased prevalence of elevated intestinal inflammation in wealthy nations, likely due to coevolutionary histories between STHs and human immune systems that favored anti-inflammatory pathways. Here, …
Biocultural Strategies for Measuring Psychosocial Stress Outcomes in Field-based Research
The goal of assessing psychosocial stress as a process and outcome in naturalistic (i.e., field) settings is applicable across the social, biological, and health sciences. Meaningful measurement of biology-in-context is, however, far from simple or straightforward. In this brief methods review, we introduce theoretical framings, methodological conventions, and ethical concerns around field-collection of markers of psychosocial stress that have em…
The application of knemometry to measure childhood short‐term growth among the indigenous Shuar of Ecuador
OBJECTIVES: Knemometry, the precise measurement of lower leg (LL) length, suggests that childhood short-term (e.g., weekly) growth is a dynamic, nonlinear process. However, owing to the large size and complexity of the traditional knemometer device, previous study of short-term growth among children has been restricted predominantly to clinical settings in industrialized Western nations. The aim of the present study is to address this limitation …
Physical activity in an indigenous Ecuadorian forager‐horticulturalist population as measured using accelerometry
OBJECTIVE: Minimal information on physical activity is available for non-Western populations undergoing the transition to a market economy. This is unfortunate given the importance of these data for understanding health issues such as the global obesity epidemic. We consider the utility of using accelerometry technology to examine activity patterns and energy use regulation among indigenous Shuar, an Ecuadorian forager-horticulturalist population…
Reproductive effects on skeletal health in Shuar women of Amazonian Ecuador
OBJECTIVE: Clinical and epidemiological research suggest that bone mineral density (BMD) in women is shaped by various reproductive factors such as parity and lactation patterns. However, the extent of these effects on BMD remains unclear because of contradictory findings and a focus on industrialized populations. Because fertility patterns in these groups are vastly different than those of women from non-Western, subsistence populations, our cur…
Analysis of variability of high sensitivity C‐reactive protein in lowland ecuador reveals no evidence of chronic low‐grade inflammation
This study is the first to investigate CRP variability in a nonindustrialized, high infectious disease environment. It documents a pattern of variation over time that is distinct from prior research, with no evidence for chronic low-grade inflammation. These results may have substantial implications for research on inflammation and diseases of aging globally, as well as for scientific understandings of the regulation of inflammation
Implications of market integration for cardiovascular and metabolic health among an indigenous Amazonian Ecuadorian population
This study provides evidence that MI among Shuar is not a uniformly negative process but instead produces complex cardiovascular and metabolic health outcomes
Sleep duration, sleep quality, and obesity risk among older adults from six middle‐income countries
OBJECTIVES: Changes in sleep patterns often occur in older adults. Previous studies have documented associations between sleep duration, sleep quality, and obesity risk in older individuals, yet few studies have examined these trends in lower-income countries. The present cross-sectional study uses nationally representative datasets from six countries to examine these relationships. METHODS: Two hypotheses related to obesity risk and sleep patter…
The impact of multimorbidity on adult physical and mental health in low- and middle-income countries
BACKGROUND: Chronic diseases contribute a large share of disease burden in low- and middle-income countries (LMICs). Chronic diseases have a tendency to occur simultaneously and where there are two or more such conditions, this is termed as 'multimorbidity'. Multimorbidity is associated with adverse health outcomes, but limited research has been undertaken in LMICs. Therefore, this study examines the prevalence and correlates of multimorbidity as…
Determining osteoporosis risk in older C olono adults from rural A mazonian E cuador using calcaneal ultrasonometry
OBJECTIVE: Low bone density and osteoporosis prevalence, while well-documented in wealthy nations, are poorly studied in rural, non-clinical contexts in economically developing regions such as Latin America. This study contributes preliminary osteoporosis risk data for a rural Colono (mestizo) population from Amazonian Ecuador. METHODS: Anthropometrics were collected for 119 adult participants (74 females, 45 males [50-90 years old]). Heel bone d…
Physical function and activity among older adults in Jodhpur, India
This study provides further evidence for a positive relationship between physical activity and functional ability among older adults and between physical activity and cardiovascular health among women in India
Accelerometer‐measured physical activity among older adults in urban I ndia
OBJECTIVES: Accelerometry provides researchers with a powerful tool to measure physical activity in population-based studies, yet this technology has been underutilized in cross-cultural studies of older adults. The present study was conducted among older adults in an urban setting in India with the following three objectives: (1) to compare average activity levels obtained through different durations of monitoring (1, 3, and 7 days); (2) to docu…
Physical growth of the shuar
OBJECTIVES: Information concerning physical growth among small-scale populations remains limited, yet such data are critical to local health efforts and to foster basic understandings of human life history and variation in childhood development. Using a large dataset and robust modeling methods, this study aims to describe growth from birth to adulthood among the indigenous Shuar of Amazonian Ecuador. METHODS: Mixed-longitudinal measures of heigh…
Perceived Income Adequacy and Well-being Among Older Adults in Six Low- and Middle-Income Countries
As expected, income adequacy was correlated with SRH and QOL. However, the relationship between age and income adequacy varied cross-culturally, potentially due to differences in familial and governmental financial support
The application of knemometry to measure childhood short‐term growth among the indigenous Shuar of Ecuador
OBJECTIVES: Knemometry, the precise measurement of lower leg (LL) length, suggests that childhood short-term (e.g., weekly) growth is a dynamic, nonlinear process. However, owing to the large size and complexity of the traditional knemometer device, previous study of short-term growth among children has been restricted predominantly to clinical settings in industrialized Western nations. The aim of the present study is to address this limitation …
Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador
This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth and health among the Shuar and other indigenous Amazonian populations
Food insecurity partially mediates associations between social disadvantage and body composition among older adults in india
OBJECTIVE: Our objective was to test whether food insecurity mediates cross-sectional associations between social disadvantage and body composition among older adults (aged 50+) in India (n = 6556). METHODS: Adjusting for key sociodemographic and dietary variables, we examined whether markers of social disadvantage (lower educational attainment, lower household wealth, belonging to a disadvantaged caste/tribe, and belonging to a minority religion…
Tradeoffs between immune function and childhood growth among Amazonian forager-horticulturalists
Significance The energetic impact of immune function on human growth remains unclear. Using data from Amazonian forager-horticulturalists, we show that diverse, low-level immune activity predicts reduced childhood growth over periods of competing energy use ranging from 1 wk to 20 mo. We also demonstrate that modest body fat stores (i.e., energy reserves) protect children from the particularly detrimental impact of acute inflammation on growth. T…
Soil‐transmitted helminth infection and intestinal inflammation among the Shuar of Amazonian Ecuador
OBJECTIVES: Little research exists documenting levels of intestinal inflammation among indigenous populations where exposure to macroparasites, like soil-transmitted helminths (STHs), is common. Reduced STH exposure is hypothesized to contribute to increased prevalence of elevated intestinal inflammation in wealthy nations, likely due to coevolutionary histories between STHs and human immune systems that favored anti-inflammatory pathways. Here, …
Disparities in bone density across contemporary Amazonian forager‐horticulturalists
OBJECTIVES: This study investigates bone density across the life course among Bolivian Tsimane and Ecuadorian Shuar of Amazonia. Both groups are rural, high-fertility forager-horticulturalists, with high lifetime physical activity levels. We test whether Tsimane and Shuar bone density patterns are different from each other, and if both groups are characterized by lower osteoporosis risk compared to U.S. references. METHODS: Anthropometric and cal…
Biocultural Strategies for Measuring Psychosocial Stress Outcomes in Field-based Research
The goal of assessing psychosocial stress as a process and outcome in naturalistic (i.e., field) settings is applicable across the social, biological, and health sciences. Meaningful measurement of biology-in-context is, however, far from simple or straightforward. In this brief methods review, we introduce theoretical framings, methodological conventions, and ethical concerns around field-collection of markers of psychosocial stress that have em…
Homeless Opioid Treatment Clients Transitioning to Dependent and Independent Housing
Purpose: Homeless opioid treatment clients who transition into housing generally demonstrate better outcomes, but housing environments vary widely and may not benefit racial/ethnic minority populations equally. We sought to identify how race/ethnicity moderates the association between positive opioid treatment response and moving into dependent or independent living environments. Methods: We used the Treatment Episode Dataset-Discharges (2018–201…
Low prevalence of anemia among Shuar communities of Amazonian Ecuador
OBJECTIVE: Anemia is an important global health challenge. We investigate anemia prevalence among Indigenous Shuar of Ecuador to expand our understanding of population-level variation, and to test hypotheses about how anemia variation is related to age, sex, and market integration. METHODS: Hemoglobin levels were measured in a total sample of 1650 Shuar participants (ages 6 months to 86 years) from 46 communities between 2008 and 2017 to compare …
Age‐related patterns of cytomegalovirus antibodies accompanying Epstein‐Barr virus co‐infection
OBJECTIVE: Cytomegalovirus (CMV) infection is associated with age-related chronic disease, and co-infection with Epstein-Barr virus (EBV) may compound disease risk. We aimed to assess the frequency of CMV infection and its relationship with age among EBV seropositive individuals in an Indigenous Amazonian population. METHODS: We report concentrations of CMV and EBV antibodies in dried blood spot samples collected from 157 EBV positive Shuar parti…
Variation in diurnal cortisol patterns among the Indigenous Shuar of Amazonian Ecuador
This study expands the documented range of global variation in HPA axis activity and diurnal cortisol production and provides important insights into the plasticity of human stress physiology across diverse developmental and socioecological settings
Soil‐Transmitted Helminths and the Intricacies of Immunoregulation
OBJECTIVES: The old friends hypothesis (OFH) examines connections between the global increase in immunoregulatory diseases (e.g., allergy and autoimmunity) and reduced exposure to immune-priming symbionts like soil-transmitted helminths. Helminth species, however, vary in their effects on hosts and should be considered separately. We examined relationships between species-specific helminth infection and circulating biomarkers of adaptive immune a…
Somatic Symptoms Are Associated With Elevated Blood Pressure and Epstein–Barr Virus Antibodies Among Shuar of the Ecuadorian Amazon
INTRODUCTION: This study tests the hypothesis that self-reported somatic symptoms are associated with biomarkers of stress, including elevated blood pressure and suppressed immune function, among Shuar adults living in the Ecuadorian Amazon. METHODS: Research was conducted in three Shuar communities in the Upano Valley of the Ecuadorian Amazon and included the collection of biomarkers and a structured morbidity interview. Participants self-report…
Testosterone, 8‐Oxo‐2′‐Deoxyguanosine (8‐OHdG) and Cu/Zn Superoxide Dismutase (SOD) in Adult Shuar Males of Amazonian Ecuador
Objectives Reproductive effort incurs the cost of biological aging and morbidity by compromising somatic maintenance when key resources are limited. Oxidative stress is positively correlated with reproductive effort in adult human females and non‐human male animal models, but human males are understudied. We hypothesized that due to its anabolic and metabolic promotion of reproductive effort in human males, testosterone would be positively associ…
Medicine (21 works) · Biology (14 works) · Demography (13 works) · Environmental health (13 works) · Indigenous (12 works) · Population (12 works) · Indigenous Health and Education (11 works) · Ecology (9 works) · Internal Medicine (9 works) · Amazon rainforest (8 works)